A comparable positioning system is known from the DE-OS No. 30 24 109 corresponding to U.S. Pat. No. 4,455,543.
The state of the art describes an actuator which is shifted back and forth between two operating positions by the alternating energizing of two actuating solenoids. An additional adjusting solenoid is provided for system startup. This adjusting solenoid is located adjacent to one of the actuating solenoids and shifts the seat of a spring system which loads the actuator system, in order to adjust the locus of equilibrium of the spring system.
With this arrangement, however, the actuating solenoid, which defines the "closed" position of the actuator, shows an uncontrolled behavior, due to interference of the magnetic fields of the two solenoids. Some examples of uncontrolled behavior which may occur include incomplete valve actuator travel preventing complete valve closure or opening, premature attraction or release of the valve actuator assembly, increase or decrease in field strength of the actuating solenoid causing valve timing delays, and the like. Such behavior may result in rough engine operation and reduced performance.
Accordingly, there is a need in the art to provide a system for reducing the uncontrolled behavior of such actuating solenoids.